This invention relates to an improvement in a container for dispensing particulate matter such as powders or finely ground fibers as, for example, talc, body powders, cosmetic face powders, soap powders or the like. In particular, this invention is directed toward the design and method of assembling such a container having a sifter-like dispensing closure which design and method is inherently simpler than prior efforts and, particularly, in the case of powders used for babies, is substantially safer.
Several designs already exist for containers to be filled with particulate matter and used for dispensing such matter through sifter means. In general these prior designs comprise a wide mouthed opening to facilitate filling and closure means which comprise two or more parts, each having a pattern of perforations therethrough, through which the particulate matter is to be dispensed in use. The pattern of perforations in at least two of the parts are so designed as to allow the user to rotate them, with respect to each other, into and out of alignment so as to open and close the container for dispensing and storage, respectively.
One such prior design is disclosed in U.S. Pat. No. 3,194,455 issued on July 13, 1965 to C. Castelli. A similar suggestion is found in U.S. Pat. No. 3,276,643 issued on Oct. 4, 1966 to M. J. Klygis. In accordance with these disclosures, a dispensing closure for a fillable container is provided and consists of two pieces; a sifter plate and a cap. The sifter plate nests within the cap and this assembly is placed over a neck surounding the fillable opening of the container. The rotation of the cap is restricted by projections provided on the outer wall of the neck which cooperate with the inner wall of the cap. By first properly registering the sifter into the cap and then properly registering the subassembly onto the neck to overlie the fillable opening of the container, the limits of rotation of both the sifter and the cap with respect to each other correspond to the open and closed position for dispensing and storage.
Unfortunately, this design presents several drawbacks. Firstly, the assembly of this closure involves two precise registration steps; the sifter into the container and the cap onto the neck of the container. Such registration steps are time consuming and expensive in terms of mass produced products such as are being considered herein. Further, this design requires precision molding of the various projections in the cap, sifter and neck all of which are difficult to accomplish, expensive and result in a high rejection rate of improperly molded parts. Perhaps most importantly, this design requires that to assemble the container, the sifter be unaffixed to either the cap or the neck. Accordingly, in the event that the cap is pried off the top of the neck, as by a child, the sifter is loose and may be dangerous to a young child, i.e., swallowed. Additionally, the total contents can be inadvertently spilled, inhaled or injested.
Several alternative suggestions have also been disclosed. In U.S. Pat. No. 2,495,806 issued to H. Block on Jan. 31, 1950, a two piece assembly has been suggested wherein a disk is riveted to the inside of a cap, both of which are provided with apertures. The disk is provided with a knob extending out of the top of the cap which may be gripped and turned thereby rotating the disk with respect to the removable, stationary cap. The travel of the disk relative to the cap into an open and closed position is controlled by a pair of projections in the disk cooperating with a pair of slots in the cap and limiting the rotation of the disk to the angle transversed by the projection between the ends of the slot. While this system does indeed simplify the molding procedure, it leaves the container entirely open should the cap be removed and hence is unsafe. Further, the riveting operation joining the disk to the cap is costly and undesirable.
In U.S. Pat. No. 1,391,772 issued on Sept. 27, 1921 to U. G. Dunham and U.S. Pat. No. 1,301,847 issued on Apr. 29, 1919 to E. Hoffman the slot/projection concept described above is utilized while still maintaining the container closed. These patents have described a three piece closure system which requires two separate registration steps and hence, for these reasons, is undesirable.
Still other suggested devices are described in U.S. Pat. Nos. 2,003,506; 3,260,426; and 3,325,066. For reasons similar to those outlined above, the suggestion found in these patents are either difficult to mold, difficult to assemble or unsafe when assembled.
Accordingly, there is a need for a simple, easy to assemble, safe sifter closure system for a fillable container.